大孔树脂分离纯化藏药白花龙胆花总黄酮的研究

考察了HPD-826、HPD-417、ADS-17、HPD-722、HPD-450、AB-8、HPD-600、D-101,共8种大孔树脂对藏药白花龙胆花总黄酮的吸附和解吸性能,通过静态吸附量和解吸附率及静态吸附曲线的绘制,筛选出AB-8树脂的效果最佳;以AB-8树脂为目标,进行了动态吸附实验,考察了上柱液浓度、pH值、上柱液流速、乙醇浓度、解吸剂流速、解吸体积等对AB-8树脂吸附和解吸效果的影响,确定出AB-8树脂动态吸附白花龙胆花总黄酮的最佳条件:上柱液浓度为6.5mg/mL,pH为3.79,上柱流速4BV/h;最佳洗脱条件:用50%乙醇进行洗脱,解吸流速为3BV/h,解吸体积4BV。在此条件下,白花龙胆花总黄酮纯度由原来的22.10%,变为65.75%,产品精制倍数为65.75%/22.10%=2.97,表明AB-8树脂可用于白花龙胆花总黄酮的分离纯化。     

吸附树脂分离纯化枇杷花总黄酮的研究

比较了D-101、D-160、AB-8、NKA-9和聚酰胺等5种吸附树脂对枇杷花总黄酮的吸附及解吸附性能。在静态吸附和动态吸附实验基础上,筛选出效果较好的AB-8树脂进行动态吸附参数的研究。考察了样品液pH值、样品液浓度、洗脱液浓度、上样速度、洗脱速度等对AB-8树脂吸附和解吸效果的影响,确定了AB-8树脂动态吸附枇杷花总黄酮的最佳条件。获得的最佳纯化条件如下,样品液pH值为5.5,样品液浓度为12mg/mL,洗脱液为30%的乙醇水溶液,上样速度为2BV/h,洗脱速度为1BV/h。纯化后样品总黄酮含量达86.7%,比纯化前总黄酮含量高5~6倍。实验结果表明,AB-8树脂可用于分离纯化枇杷花总黄酮。     

大孔树脂纯化脱油油樟叶渣中总黄酮工艺研究

本研究以从脱油油樟叶渣中提取出的总黄酮粗提液为原料,采取静态吸附-解吸实验对5种大孔树脂进行筛选,选取最佳型号的大孔树脂AB-8进行实验,通过单因素试验选择出最佳纯化工艺条件。研究结果表明,最佳吸附和解吸条件:避光振摇下吸附时间为10h,避光振摇下解吸附时间为6h,样品溶液的pH值为5,洗脱液乙醇溶液浓度为80%,上样液中总黄酮浓度为0.5mg/mL,上样量为2.5BV,洗脱流速为1mL/min,洗脱量为2.5BV;在最佳条件下得到脱油油樟叶渣中总黄酮质量分数为(72.4±0.5)%。该方法简单可行,为脱油油樟叶渣中总黄酮的开发利用提供了技术参考与借鉴。     

大孔树脂对发酵液中松脂醇二葡萄糖苷的吸脱附性能

考察了S-8、AB-8、NKA-II、NKA-9 4种大孔吸附树脂对杜仲内生真菌拟茎点霉属XP-8发酵液中松脂醇二葡萄糖苷(Pinoresinol Diglucoside,PDG)的吸附和脱附性能,筛选出S-8树脂的吸附和脱附性能最好;探讨了S-8树脂在静态吸附条件下对发酵液中PDG的吸附平衡和吸附动力学,考察了温度和pH值对吸附效果的影响;进行了动态吸附实验,确定了最佳吸附和洗脱条件。结果表明,在静态吸附条件下,Langmuir方程可很好地描述PDG在S-8树脂上的吸附平衡,液膜扩散和颗粒内扩散分别是控制吸附初期和后期吸附速率的主要步骤;动态吸附的最佳条件是,上样浓度为0.195mg/mL、上样温度为20℃、pH 9、进样流速1BV/h,溶液处理量20BV;最佳动态洗脱条件是,洗脱液为30%的乙醇水溶液,洗脱液流速1BV/h,用量为6BV。整个动态吸附洗脱过程结束后的PDG得率为89.8%。     

大孔吸附树脂分离纯化仙人掌中总黄酮的研究

考察了4种大孔吸附树脂对仙人掌总黄酮的吸附分离性能,筛选出效果最佳的树脂为AB-8。以总黄酮的吸附量、总黄酮含量和回收率为考察指标,采用紫外分光光度法测定总黄酮。确定了AB-8树脂吸附分离仙人掌总黄酮的工艺条件:上样浓度为15mg/mL,仙人掌总黄酮最大吸附量为18.6mg/mL,吸附流速为5mL/min,洗脱剂为70%乙醇,洗脱剂用量为6倍柱体积,树脂可重复使用3次。经AB-8树脂分离纯化后,总黄酮含量从29%提高到76%,总黄酮回收率为86%。实验结果表明,AB-8树脂可用于仙人掌总黄酮的分离纯化。     

大孔树脂分离纯化楮果总黄酮优化工艺研究

筛选适合分离纯化楮果总黄酮的大孔树脂并确定最优工艺条件。以静态吸附率和解吸率为指标对8种大孔树脂进行筛选,确定D101树脂的分离纯化效果最佳。通过动态吸附实验考察上样流速、上样溶液pH值、上样溶液浓度、乙醇浓度、洗脱流速、洗脱剂用量等工艺条件对分离纯化效果的影响,确定最优工艺条件如下:上样流速为2BV/h,pH值为6,上样溶液浓度为0.05mg/mL,80%乙醇作洗脱剂,洗脱流速为5BV/h,洗脱剂用量为7.5BV。采用最优工艺条件,楮果总黄酮含量提高至22.26%,产品精制倍数为4.79,表明D101树脂能有效纯化楮果总黄酮。     

正交法优化大孔树脂提纯罗布麻中总黄酮的工艺

采用正交试验法,优选大孔树脂提纯罗布麻中总黄酮的最佳工艺。以芦丁为对照品,采用分光光度法进行测定,以罗布麻中总黄酮回收率为考察指标,对影响总黄酮纯化工艺的因素进行研究;在单因素实验基础上,选择树脂种类、p H值、料液浓度、解吸液乙醇浓度等4个因素进行正交试验,研究不同因素交互作用及其对黄酮回收率的影响,结合吸附和解吸流速,确定罗布麻总黄酮提纯的最佳工艺;用高效液相色谱法对提纯前后芦丁含量进行比较,验证纯化效果。经正交试验,确定最佳工艺参数如下:AB-8树脂,料液浓度为0.125mg/mL,p H=5,吸附流速为3mL/min,解吸液乙醇浓度为80%,解吸流速为5mL/min。在此工艺条件下,总黄酮产率为2.64%,总黄酮含量由10.1mg/g提高到378.6mg/g;经高效液相色谱法计算,芦丁含量由6.3mg/g提高到185.6mg/g。     

火棘果总黄酮的提取和纯化研究

采用溶剂提取法、索氏提取法、循环超声提取法提取火棘果总黄酮,利用静态吸附方法筛选分离火棘果总黄酮的最适大孔树脂,利用动态吸附方法研究最适大孔树脂纯化火棘果总黄酮的条件,并用紫外分光光度法测定其含量。得出结果为循环超声提取时间短、效率高;D101大孔吸附树脂纯化效果最好,最佳工艺为上样浓度为0.899 8g·L-1,上样液pH为4,上样体积5BV,上样速率2.5mL·min-1,用5BV70%乙醇以2.0 mL·min-1速率洗脱,经树脂纯化后总黄酮的纯度由原来的9.00%提高至28.11%。     

大孔吸附树脂分离纯化昆仑雪菊总黄酮工艺的研究

筛选分离纯化昆仑雪菊总黄酮的大孔吸附树脂并建立纯化工艺条件。以大孔吸附树脂对昆仑雪菊总黄酮的吸附量、吸附率和解吸率等为指标,考察了11种型号的大孔吸附树脂进行分离纯化,并确定了该树脂分离纯化最佳工艺参数。结果显示NKA-9型大孔吸附树脂对昆仑雪菊总黄酮分离纯化效果好,其工艺条件为:以pH值为5.0的原料液上柱吸附,70%浓度的乙醇洗脱、洗脱速度3mL·min-1,在此条件下总黄酮的的静态吸附率为95.74%,解吸率为98.9%。     

Chelex 100和Chilete P树脂分离水中Sr2+离子的研究

通过对Chelex 100和Chilete P两种螯合树脂对水中Sr2+离子的静态和动态分离研究,考察浓度、pH值、体积和流速等条件的影响,设计正交实验,摸索树脂动态吸附和洗脱的工艺路线。结果表明:Chelex 100比Chilete P具有更好的Sr2+离子吸附效果,静态分离回收率分别为71.48%和51.49%。Chelex 100树脂的动态分离工艺:浓度为250mg·mL-1、pH值为3的Sr2+离子溶液20mL,以流速为3ml.min-1通过层析柱吸附;8mol.L-1的HNO3溶液以流速为2ml.min-1进行Sr2+离子的洗脱;获得最终回收率为87.08%。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.